## SNIIX18 2 years ago If the period of a pendulum is 2.0 seconds and the acceleration due to gravity is 9.8 meters/second^2, What is the length of the cord on the pendulum? A)1.0 meters B)0.67 meters C)1.3 meters D)3.5 meters

1. SNIIX18

can you help me

2. theEric

Are you speaking of a simple pendulum?

3. SNIIX18

YES

4. theEric

Then you'll want the equation that uses math to describe the relationships between different physical quantities. I think I've show it to you before. I found it at http://hyperphysics.phy-astr.gsu.edu/hbase/pend.html It is:$T=2\pi\sqrt{\frac{L}{g}}$ $$T$$ is the period. $$L$$ is the length of the chord. $$g$$ is the acceleration caused by gravity. You want to solve for $$L$$.

5. SNIIX18

OKAY HOLD ON

6. SNIIX18

I GOT O.67 IS THAT RIGHT

7. theEric

It's not what I got! How did you solve for $$L$$?

8. SNIIX18

I squared 2 then i divided 2.0 by 9.8

9. theEric

I'm confused... Can you show me what you got? You squared the 2?

10. SNIIX18

now im confused cause your confused

11. theEric

Haha, you start with $T=2\pi\sqrt{\frac{L}{g}}$Now, what did you square?

12. SNIIX18

owwww okay i see what i did wrong i was suppost to pi the 2 instead of square

13. theEric

Hmmm?

14. theEric

I would divide the equation by $$2\pi$$, square the equation, and multiply the equation by $$g$$, if you know what I mean. Then you have $$L$$ by itself after applicable cancelations, if you know what I mean.